The present invention relates to a work conveying apparatus for a clean room and, more particularly, to a work conveying system for transporting works between processing chambers in an intra-clean room production line for, e.g., semiconductor parts, liquid crystal display panels, medicines, chemicals, or processed food.
The yield of semiconductor integrated circuits, liquid crystal display panels, and the like lowers by adhesion of dust. Also, medicines, chemicals, processed food, and the like are desirably produced in a germ-free, sanitary environment. For this purpose, intra-clean room production lines are operating in a wide variety of fields including such production departments. Various techniques have been developed for diverse processing chambers and conveying systems to be installed in a clean room.
(First Prior Art)
FIG. 1 is a perspective view showing an example of conventionally proposed intra-clean room production facilities. Reference numeral 1 denotes the floor surface of a clean room. In this clean room, a plurality of processing chambers 2 are arranged in order. An interface apparatus 3 for loading and unloading works into and from each processing chamber 2 is installed adjacent to each processing chamber 2. On the clean room floor surface 1, a guide path (track) 4 is laid down to pass in front of each interface apparatus 3. An automatic guided vehicle (AGV) 5 runs on the floor along this guide path 4.
In this clean room, works are conveyed from the interface apparatus 3 of one processing chamber 2 to the interface apparatus 3 of another processing chamber 2 by the automatic guided vehicle 5. Each interface apparatus (work loading/unloading apparatus) 3 shields the interior of the processing chamber 2 from the clean room. The works loaded into the processing chamber 2 by the interface apparatus 3 are subjected to predetermined processing meeting the purpose of the processing chamber 2. The works processed in the processing chamber 2 are extracted from the processing chamber 2 by the interface apparatus 3 and loaded onto the automatic guided vehicle 5. The works thus completely processed in one processing chamber 2 are transported to the next processing chamber 2, loaded into this processing chamber 2 by the interface apparatus 3, and subjected to predetermined processing. In this manner, works are sequentially subjected to predetermined processing in the clean room.
When a work conveying system with this arrangement is used, however, it is necessary to secure in the clean room a sufficiently wide transfer area capable of allowing the automatic guided vehicle 5 to safely run without colliding against the processing chambers 2, the interface apparatuses 3, or maintenance workers, in addition to the installation area of the processing chambers 2 and the interface apparatuses 3. In other words, to allow continuous operation by reducing the rate of inconveniences in the intra-clean room production line, maintenance of diverse apparatuses such as the processing chambers 2 and the interface apparatuses 3 is necessary. Therefore, a sufficient area is required to permit safe maintenance with no collisions against the automatic guided vehicle 5.
For this reason, a clean room using the work conveying system as shown in FIG. 1 occupies a large area on the floor. This increases the installation cost and operation cost per unit volume of the clean room, resulting in a very expensive clean room as a whole.
(Second Prior Art)
FIG. 2 is a perspective view showing another conventional installation in a clean room. This intra-clean room installation uses an overhead type automatic guided vehicle 7. That is, an overhead rail 6 is laid below the ceiling of the clean room, and the monorail type automatic guided vehicle 7 runs along this overhead rail 6. This automatic guided vehicle 7 runs above each interface apparatus 3 along its front surface.
In this intra-clean room installation, the automatic guided vehicle 7 passes at a level above a floor surface 1, which is much higher than human heights. Hence, the possibility of collisions between this automatic guided vehicle 7 and maintenance workers and the like is zero. Accordingly, an area below the space in which the automatic guided vehicle 7 runs can be used to perform, e.g., maintenance of processing chambers 2 and inspection of works. Consequently, the floor area of the clean room can be reduced, and this can reduce the installation cost and operation cost of the clean room. This type of clean room is disclosed in, e.g., Japanese Patent Laid-Open No. 9-312322.
(Third Prior Art)
Japanese Patent Laid-Open No. 10-250836 has disclosed a system in which an automatic guided vehicle disposed in the upper space of a clean room runs above interface apparatuses. With this arrangement, it is necessary to secure only a maintenance area for performing maintenance between processing chambers each having the interface apparatus. A floor area occupied by the maintenance area is smaller than that of the area for running the automatic guided vehicle. Therefore, when the automatic guided vehicle runs above the interface apparatuses and it is only necessary to secure the maintenance area between the individual processing chambers, the necessary floor area can be smaller than the intra-clean room installation shown in FIG. 2. This can further reduce the cost of the clean room.
Unfortunately, the transfer path is fixed in any of the work conveying systems used in the conventional intra-clean room facilities as described above. When the transfer path of the work conveying system is thus fixed, the installation positions of the processing chambers and interface apparatuses are limited by this transfer path. So, it is not necessarily possible to optimally arrange the processing chambers and interface apparatuses in the clean room. That is, the interface apparatus adjacent to the processing chamber must be installed immediately below, or in the vicinity of, the transfer path installed in the clean room. Also, the position and direction of the processing camber depend on the position of the interface apparatus, i.e., they cannot be freely changed. Even when a new processing chamber is to be added, the arrangement of individual processing chambers and their interface apparatuses cannot be freely designed, so the installation positions may be unavoidably changed. Especially in an expensive clean room, the space cannot be given any margin from the beginning. This makes designing the installation positions more and more difficult.
In the fields of semiconductor devices and liquid crystal display panels, the lifecycles of products shorten year by year by the advent of new methods and new structures. Hence, the factory installations must be refined frequently. This factory installation refinement is desirably performed at minimum cost. In practice, however, the existing work conveying system restricts the installation positions of interface apparatuses. Therefore, considerable limitations are still imposed on replacement, change of the arrangement, and addition of processing chambers or interface apparatuses when the process is changed, and the cost increases accordingly.
The present invention has been made to solve the above technical problems, and has as its object to provide a clean room work conveying system capable of reducing limitations on the installation positions of apparatuses in a clean room, and allowing effective use of the space in the clean room.
According to the present invention, there is provided a work conveying system for conveying works in a clean room, comprising a work holder for holding works, and moving means for moving the work holder.
In the work conveying system of the present invention, the moving means desirably moves the work holder in an arbitrary three-dimensional direction in a space above the floor of the clean room.
Since the work holder for holding and conveying works moves in the upper space of the clean room, no area is necessary for work transfer on the floor of the clean room. This makes effective use of the clean room feasible. Accordingly, a necessary clean room volume can be decreased for the same installation. This can reduce the installation cost and operation cost of the clean room.
Also, the moving means can move the work holder in an arbitrary three-dimensional direction. Therefore, the installation positions and installation directions of apparatuses such as processing chambers installed in the clean room are not easily limited, so an optimum arrangement can be selected. Additionally, when a new processing chamber or the like is to be added or when the arrangement of apparatuses such as processing chambers is to be changed, the arrangement or installation directions can be freely chosen. Hence, it is possible to reduce the cost for changing the arrangement of apparatuses such as processing chambers or for adding a new apparatus.
Furthermore, when the work holder is moved above apparatuses such as the processing chambers, this work holder can be moved straight from one position to another. This improves the processing efficiency in the clean room.
In the work conveying system of the present invention, the moving means desirably moves the work holder in an arbitrary direction in a substantially horizontal plane in a space above the floor of the clean room, and the work conveying system desirably further comprises work lifting means added to an apparatus installed in the clean room to load/unload works with respect to the work holder and move works up and down.
In this system, the work holder for holding works horizontally moves in the upper space of the clean room, and the work lifting means of an apparatus such as a processing chamber moves up to the height of the work holder and loads/unloads works with respect to the work holder. This obviates an area for work transfer on the floor of the clean room and makes effective use of the clean room possible. Accordingly, a necessary clean room volume can be decreased for the same installation. This can reduce the installation cost and operation cost of the clean room.
Also, the moving means can move the work holder in an arbitrary three-dimensional direction. Therefore, the installation positions and installation directions of apparatuses such as processing chambers installed in the clean room are rarely limited, so an optimum arrangement can be selected. Additionally, when a new processing chamber or the like is to be added or when the arrangement of apparatuses such as processing chambers is to be changed, the arrangement or installation directions can be freely chosen. Hence, it is possible to reduce the cost for changing the arrangement of apparatuses such as processing chambers or for adding a new apparatus.
Since the moving means does not require any function of moving the work holder up and down, the installation space height of the moving means can be decreased. This can further reduce the installation cost and operation cost of the clean room.
Furthermore, the work holder can load/unload works with respect to the work lifting means only by horizontal movement and can immediately proceed on to an operation for another work transfer while allowing the work lifting means to raise or lower the works. This can increase the speed of work transfer.
The apparatus installed in the clean room can comprise a plurality of work loading/unloading units, and the work lifting means can move along these work loading/unloading units.
In this case, in order to improve the operation efficiency, the work lifting means can move along the work loading/unloading units with respect to the apparatus such as a processing chamber including these work loading/unloading units. Therefore, the work lifting means which has received works can move to and load/unload the works with respect to a work loading/unloading unit capable of receiving works. Additionally, the number of the work loading/unloading means is smaller than the number of the work loading/unloading units, so the cost decreases.
Also, in the work conveying system of the present invention, the moving means desirably moves the work holder in an arbitrary direction in a substantially horizontal plane at a height substantially equal to the work loading/unloading height of an apparatus installed in the clean room.
In this system, the work holder for holding works horizontally moves in the upper space of the clean room, and the work lifting means of an apparatus such as a processing chamber moves up to the height of the work holder and loads/unloads works with respect to the work holder. This obviates an area for work transfer on the floor of the clean room and makes effective use of the clean room possible. Accordingly, a necessary clean room volume can be decreased for the same installation. This can reduce the installation cost and operation cost of the clean room.
Also, the moving means can move the work holder in an arbitrary three-dimensional direction. Therefore, the installation positions and installation directions of apparatuses such as processing chambers installed in the clean room are rarely limited, so an optimum arrangement can be selected. Additionally, when a new processing chamber or the like is to be added or when the arrangement of apparatuses such as processing chambers is to be changed, the arrangement or installation directions can be freely chosen. Hence, it is possible to reduce the cost for changing the arrangement of apparatuses such as processing chambers or for adding a new apparatus.
Since the moving means does not have any function of moving the work holder up and down, the installation space height of the moving means can be decreased. This can further reduce the installation cost and operation cost of the clean room.
Furthermore, in this work conveying system, the work holder does not perform any lifting operation. This can increase the speed of work transfer.
The work conveying system of the present invention desirably further comprises a controller for automatically selecting, on the basis of input information, a path along which the moving means moves the work holder.
As the input information, process content information and arrangement information of apparatuses such as processing chambers are input. On the basis of these pieces of information and various pieces of previously input information about, e.g., work transfer and disturbance of air in the clean room, the controller automatically selects a transfer path in accordance with a predetermined algorithm. This allows work transfer which minimizes disturbance of the cleanliness in the clean room.
In the work conveying system of the present invention, works are desirably sealed in a container, and the container is desirably held by the work holder and conveyed by the moving means.
Since works are conveyed as they are sealed in the container, a necessary level of the cleanliness in the clean room can be lowered by raising the cleanliness in the container. Consequently, the installation cost and operation cost of the clean room can be reduced.
In the work conveying system of the present invention, the moving means is desirably capable of moving works from one apparatus to another installed in the clean room via a work standby place for temporarily stocking works.
In this case, works can be conveyed from one apparatus to another installed in the clean room via the work standby place. Hence, if an apparatus as the transfer destination is processing other works, another work transfer can be performed while the works to be conveyed are temporarily stocked in the work standby place. This can improve the operation efficiency of work processing.
In the work conveying system of the present invention, the moving means desirably comprises a second member which moves with respect to a first member, and non-contact power supply means desirably supplies electric power from the first member to the second member.
In this system, the non-contact power supply means supplies electric power in a movable portion between the members. Therefore, no dust is produced by sliding in the power supply portion, so the cleanliness in the clean room does not lower.
In the work conveying system of the present invention, the moving means desirably comprises a second member which moves with respect to a first member, and the second member desirably runs with respect to the first member by a linear motor.
In this system, the movable member (second member) is moved by the linear motor in a movable portion between the members. Since this linear motor uses magnetic repulsive force, the second member can be moved as it is floated from the first member. Accordingly, no dust is produced in the movable portion of the moving means, so the cleanliness in the clean room does not lower.
In the work conveying system of the present invention, the moving means desirably comprises a portion in which a slider of a second member is accommodated, so as to be able to freely run, in a traveling space formed in a first member, and a gap between a connecting member extending from the slider to the outside of the first member and the first member desirably bends.
In this system, the gap between the connecting member extending from the slider housed in the first member to the outside of the first member and the first member bends. Hence, dust produced in the contact portion between the first member and the slider is not easily discharged outside the first member through the gap, so the clean room is not easily contaminated. Also, since the slider which can freely run is accommodated in the first member, dust produced by contact is not released outside the first member while the slider is running.
In the work conveying system of the present invention, the moving means desirably comprises exhausting means for exhausting air inside the moving means to the outside of the clean room.
Since the moving means includes the exhausting means for exhausting air inside the moving means to the outside of the clean room, dust produced inside the moving means, particularly in movable portions can be forcedly discharged to the outside of the clean room. Therefore, the cleanliness of the clean room does not easily lower by the work conveying system.
In this system, the moving means can have a substantially closed structure as a whole, and portions of the moving means can communicate with each other.
Since the moving means has a substantially closed structure as a whole and portions of this moving means communicate with each other, dust produced inside the moving means can be forcedly discharged outside the clean room, with no leakage to the clean room, by the exhausting means.
In the work conveying system of the present invention, the work holder can comprise a conveyor for loading and unloading works.
In this system, the work holder includes the conveyor for loading and unloading works. Accordingly, this conveyor of the work holder can load/unload works with respect to an apparatus such as an interface apparatus. This makes smooth work loading/unloading possible.
In the work conveying system of the present invention, the work holder desirably comprises a sensor for sensing contact with an apparatus installed in the clean room.
In this system, the work holder includes the sensor for sensing contact with an apparatus installed in the clean room. Therefore, if this work holder comes in contact with another apparatus such as a processing chamber or an interface apparatus, the sensor can sense this contact and stop the work holder or make the work holder detour. This can prevent the work holder from colliding against another apparatus to result in serious damage.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.